Lim Sung-Hwan, Ra Tae-Yeub, Kim Won-Yong
J Electron Microsc (Tokyo). 2003;52(5):459-64. doi: 10.1093/jmicro/52.5.459.
The contact resistance of Au/Ni/p-GaN ohmic contacts for different annealing conditions was measured. This was then correlated with microstructure, including phase distribution, observed by high-resolution electron microscopy combined with energy-filtering imaging. A contact resistance of 2.22 x 10(-4) ohms cm2 for Au/Ni contacts to p-GaN after annealing at 500 degrees C for 5 min in air ambient was obtained. NiO layers were identified at the interface and upper area of annealed Ni/Au/p-GaN for air ambient. In addition, an Au layer was found at the interface of p-GaN due to a reversal reaction during annealing. Identification of the observed phases is discussed, along with possible formation mechanisms for the ohmic contacts in the Au/Ni/p-GaN system.
测量了不同退火条件下Au/Ni/p-GaN欧姆接触的接触电阻。然后将其与通过高分辨率电子显微镜结合能量过滤成像观察到的微观结构（包括相分布）相关联。在空气环境中于500℃退火5分钟后，Au/Ni与p-GaN接触的接触电阻为2.22×10(-4) 欧姆·厘米2。在空气环境中退火的Ni/Au/p-GaN的界面和上部区域发现了NiO层。此外，由于退火过程中的逆反应，在p-GaN的界面处发现了一层Au。讨论了观察到的相的识别，以及Au/Ni/p-GaN系统中欧姆接触的可能形成机制。
